I have a code like below
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13)
{
if (!textBox1.AcceptsReturn)
{
button1.PerformClick();
}
}
}
After I hit Enter, it'll send a message to another textbox and begin a new line. Can anyone help me to bring the cursor back to its first line?
I tried textBox1.SelectionStart, SelectionLength and Focus but it doesn't work, is there any another way?
You can prevent that the keypress is passed on to the control by setting the KeyPressEventArgs.Handled property to true:
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == 13)
{
if (!textBox1.AcceptsReturn)
{
button1.PerformClick();
e.Handled = true;
}
}
}
As you mentioned in a comment that you are implementing a chat app, you also might want to implement the typical behavior of Shift+Return inserting a new line:
private void textBox1_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyValue == 13 && !e.Shift)
{
if (!textBox1.AcceptsReturn && !string.IsNullOrEmpty(textBox1.Text))
{
button1.PerformClick();
textBox1.Text = "";
e.Handled = true;
}
}
}
To set cursor position to the beginning of a textbox, use the following...
I will hazard a guess that you didn't use these in combination with each other...
textBox1.SelectionStart = 0;
textBox1.SelectionLength = 0;
I made a KeyPress Event and want to allow only Double values (or just digits and comma) so I tried this:
e.Handled = !(char.IsNumber(e.KeyChar) || e.KeyChar == (char)Keys.Back || e.KeyChar == (char)Keys.Decimal);
But somehow he's got problems with the "Decimal". I'm using a german keyboard and when I try to enter the comma, he does nothing. When I press the "n" key he writes the letter. What is wrong here and how to solve that?
you can restrict the input using keyPress event like so:
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
char c= e.KeyChar;
if (!char.IsDigit(c) && !char.IsControl(c))
{
e.Handled = true;
}
}
if we want to extend our restriction condition to accept a certain character (for example ,)
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
char c= e.KeyChar;
if (!char.IsDigit(c) && !char.IsControl(c) && c!=',')
{
e.Handled = true;
}
}
To avoid having multiple comma like 222,34545,454 we can do this work around:
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
char c= e.KeyChar;
bool comma= textBox1.Text.Contains(','); //true in case comma already inserted
// accepts only digits, controls and comma
if (!char.IsDigit(c) && !char.IsControl(c) && c!=',')
{
e.Handled = true;
return;
}
// whenever a comma is inserted we check if we already have one
if (c == ',' && comma)
{
e.Handled = true;
}
}
I'm making a textbox to input some Product's Price, and I don't want the user to input "." more than once. "." can not be the first character (which I know how to do). But I need to make the textbox accept this character "." not more than once. How ? And no, I don't want to use MaskedTextBox.
Put it in KeyPress event in your textbox.
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
string inputChar = e.KeyChar.ToString();
if (inputChar == ".")
{
if (textBox1.Text.Trim().Length == 0)
{
e.Handled = true;
return;
}
if (textBox1.Text.Contains("."))
{
e.Handled = true;
}
}
}
Try this
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (textBox1.Text.IndexOf('.') != textBox1.Text.LastIndexOf('.'))
{
MessageBox.Show("More than once, not allowed");
textBox1.Text = textBox1.Text.Substring(0, textBox1.Text.Length - 1);
}
}
This is the code I currently have:
private void textBox_KeyPress(object sender, KeyPressEventArgs e)
{
e.Handled = !char.IsDigit(e.KeyChar) && !char.IsControl(e.KeyChar) && e.KeyChar != '.';
if (e.KeyChar == '.' && (sender as TextBox).Text.IndexOf('.') > -1) e.Handled = true;
}
KeyPress isn't good enough to do this kind of validation. A simple way to bypass it is to paste text into the text box with Ctrl+V. Or the context menu, no key event at all.
In this specific case, the TextChanged event will get the job done:
private void textBox_TextChanged(object sender, EventArgs e) {
var box = (TextBox)sender;
if (box.Text.StartsWith(".")) box.Text = "";
}
But there's a lot more to validating numeric values. You also need to reject stuff like 1.1.1 or 1.-2 etcetera. Use the Validating event instead. Drop an ErrorProvider on the form and implement the event like this:
private void textBox_Validating(object sender, CancelEventArgs e) {
var box = (TextBox)sender;
decimal value;
if (decimal.TryParse(box.Text, out value)) errorProvider1.SetError(box, "");
else {
e.Cancel = true;
box.SelectAll();
errorProvider1.SetError(box, "Invalid number");
}
}
You probably want to use the TextChanged event, since the user could paste in values. For the best experience given the requirements, I'd suggest simply removing any leading . characters.
void textBox1_TextChanged(object sender, EventArgs e)
{
if (textBox1.Text.StartsWith("."))
{
textBox1.Text = new string(textBox1.Text.SkipWhile(c => c == '.').ToArray());
}
}
This does not address a requirement to use only digits -- wasn't clear in the question if that is the case.
This works for copy and pasting too.
private void textBox1_KeyUp(object sender, KeyEventArgs e)
{
int decimalCount=0;
string rebuildText="";
for(int i=0; i<textBox1.Text.Length; i++)
{
if (textBox1.Text[i] == '.')
{
if (i == 0) break;
if (decimalCount == 0)
rebuildText += textBox1.Text[i];
decimalCount++;
}
else if ("0123456789".Contains(textBox1.Text[i]))
rebuildText += textBox1.Text[i];
}
textBox1.Text = rebuildText;
textBox1.SelectionStart = textBox1.Text.Length;
}
You can try this:
private void TextBox_TextChanged(object sender, EventArgs e)
{
TextBox.Text = TextBox.Text.TrimStart('.');
}
How can I make a TextBox only accept alphabetic characters with spaces?
You could use the following snippet:
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (!System.Text.RegularExpressions.Regex.IsMatch(textBox1.Text, "^[a-zA-Z ]"))
{
MessageBox.Show("This textbox accepts only alphabetical characters");
textBox1.Text.Remove(textBox1.Text.Length - 1);
}
}
You can try by handling the KeyPress event for the textbox
void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back);
}
Additionally say allow backspace in case you want to remove some text, this should work perfectly fine for you
EDIT
The above code won't work for paste in the field for which i believe you will have to use TextChanged event but then it would be a bit more complicated with you having to remove the incorrect char or highlight it and place the cursor for the user to make the correction Or maybe you could validate once the user has entered the complete text and tabs off the control.
private void textbox1_KeyDown_1(object sender, KeyEventArgs e)
{
if (e.Key >= Key.A && e.Key <= Key.Z)
{
}
else
{
e.Handled = true;
}
}
The simplest way is to handle the TextChangedEvent and check what's been typed:
string oldText = string.Empty;
private void textBox2_TextChanged(object sender, EventArgs e)
{
if (textBox2.Text.All(chr => char.IsLetter(chr)))
{
oldText = textBox2.Text;
textBox2.Text = oldText;
textBox2.BackColor = System.Drawing.Color.White;
textBox2.ForeColor = System.Drawing.Color.Black;
}
else
{
textBox2.Text = oldText;
textBox2.BackColor = System.Drawing.Color.Red;
textBox2.ForeColor = System.Drawing.Color.White;
}
textBox2.SelectionStart = textBox2.Text.Length;
}
This is a regex-free version if you prefer. It will make the text box blink on bad input.
Please note that it also seems to support paste operations as well.
Write Code in Text_KeyPress Event as
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsLetter(e.KeyChar))
{
e.Handled = true;
}
}
This one is working absolutely fine...
private void manufacturerOrSupplierTextBox_KeyPress(object sender, KeyPressEventArgs e)
{
if (char.IsControl(e.KeyChar) || char.IsLetter(e.KeyChar))
{
return;
}
e.Handled = true;
}
This solution uses regular expressions, does not allow invalid characters to be pasted into the text box and maintains the cursor position.
using System.Text.RegularExpressions;
int CursorWas;
string WhatItWas;
private void textBox1_Enter(object sender, EventArgs e)
{
WhatItWas = textBox1.Text;
}
private void textBox1_TextChanged(object sender, EventArgs e)
{
if (Regex.IsMatch(textBox1.Text, "^[a-zA-Z ]*$"))
{
WhatItWas = textBox1.Text;
}
else
{
CursorWas = textBox1.SelectionStart == 0 ? 0 : textBox1.SelectionStart - 1;
textBox1.Text = WhatItWas;
textBox1.SelectionStart = CursorWas;
}
}
Note: textBox1_TextChanged recursive call.
if (System.Text.RegularExpressions.Regex.IsMatch(textBox1.Text, "^[a-zA-Z]+$"))
{
}
else
{
textBox1.Text = textBox1.Text.Remove(textBox1.Text.Length - 1);
MessageBox.Show("Enter only Alphabets");
}
Please Try this
private void textBox2_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar >= '0' && e.KeyChar <= '9')
e.Handled = true;
else
e.Handled = false;
}
Try This
private void tbCustomerName_KeyPress(object sender, KeyPressEventArgs e)
{
e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back||e.KeyChar==(char)Keys.Space);
}
It Allows White Spaces Too
you can try following code that alert at the time of key press event
private void tbOwnerName_KeyPress(object sender, KeyPressEventArgs e)
{
//===================to accept only charactrs & space/backspace=============================================
if (e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back || e.KeyChar == (char)Keys.Space))
{
e.Handled = true;
base.OnKeyPress(e);
MessageBox.Show("enter characters only");
}
Here is my solution and it works as planned:
string errmsg = "ERROR : Wrong input";
ErrorLbl.Text = errmsg;
if (e.Handled = !(char.IsLetter(e.KeyChar) || e.KeyChar == (char)Keys.Back || e.KeyChar == (char)Keys.Space))
{
ErrorLbl.Text = "ERROR : Wrong input";
}
else ErrorLbl.Text = string.Empty;
if (ErrorLbl.Text == errmsg)
{
Nametxt.Text = string.Empty;
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (!char.IsControl(e.KeyChar) && !char.IsLetter(e.KeyChar) &&
(e.KeyChar !='.'))
{
e.Handled = true;
MessageBox.Show("Only Alphabets");
}
}
Try following code in KeyPress event of textbox
if (char.IsLetter(e.KeyChar) == false &
Convert.ToString(e.KeyChar) != Microsoft.VisualBasic.Constants.vbBack)
e.Handled = true
works for me, even though not the simplest one.
private void Alpha_Click(object sender, EventArgs e)
{
int count = 0;
foreach (char letter in inputTXT.Text)
{
if (Char.IsLetter(letter))
{
count++;
}
else
{
count = 0;
}
}
if (count != inputTXT.Text.Length)
{
errorBox.Text = "The input text must contain only alphabetic characters";
}
else
{
errorBox.Text = "";
}
}
This works fine as far as characters restriction, Any suggestions on error msg prompt with my code if it's not C OR L
Private Sub TXTBOX_TextChanged(sender As System.Object, e As System.EventArgs) Handles TXTBOX.TextChanged
Dim allowed As String = "C,L"
For Each C As Char In TXTBOX.Text
If allowed.Contains(C) = False Then
TXTBOX.Text = TXTBOX.Text.Remove(TXTBOX.SelectionStart - 1, 1)
TXTBOX.Select(TXTBOX.Text.Count, 0)
End If
Next
End Sub
Try this one. Spaces and shortcut keys work
if (!char.IsControl(e.KeyChar) && !char.IsLetter(e.KeyChar) && !char.IsSeparator(e.KeyChar))
{
e.Handled = true;
}